Cancer researchers are presently armed with extraordinary tools for understanding the genetic and environmental causes of carcinogenesis. The design, execution, and interpretation of these research projects require input from teams of scientists with a mixture of backgrounds, including molecular biology, oncology, medicine, genetics, epidemiology, and biostatistics. Individuals with trans-disciplinary education across these fields are crucial to the success of such teams. In particular, they can serve as the conduit for the integrated work necessary to accomplish some of the most promising research. However, the focused nature of existing training opportunities provides limited opportunities for investigators to obtain the knowledge that bridges these disciplines. To address this issue, we propose developing an inter-institutional training program in Genetic &Molecular Epidemiology of Cancer (GMEC). Mentors and research training opportunities will come from major academic and research institutions in the San Francisco Bay Area, including the University of California, San Francisco and Berkeley, Kaiser Permanente and the Northern California Cancer Center. The proposed program is uniquely suited to the R25T grant mechanism because it will train scientists in the interdisciplinary field of genetic and molecular epidemiology. More specifically, the GMEC program will blend together in a highly interactive fashion a group of mentors and trainees from cancer research, molecular biology, genetics, epidemiology, biostatistics, and pharmacogenomics. The program is defined by a specialized core curriculum, additional educational experiences, and focused research projects with multiple mentors. Each trainee will also be required to extend their research experience by writing a mock NIH proposal. Individuals trained in this program will have the skills vital to understanding the causes of disease, ultimately providing valuable information for the treatment and prevention of cancer.